Fair point, Swift will never be as predictable or efficient as Rust (not a negative perse, just different goals). But I disagree on the complexity re: Go. What about Swift gives you the impression of extreme complexity? Go is definitely comparatively simpler but I do not think it is so much so as to put it in a different league.
Also swift as a language doesn't scale well. There are a lot of bottlenecks in the build process that doesn't let you scale simply amongst many cores like you can with C++, Obj-C & C and probably many other languages too. You're also effectively limited to xcode & apple desktops, so you can't go rent out a 100 core build server on AWS for builds like you can for every other platform out there, not that is matters much yet with swift's build scaling issues.
Also stuff like basic debugging often just... dies.
The more I work with a badly scaling language the more I appreciate a design decision like go made with building fast. I hope with generics in go v2 the boilerplate should reduce a lot.
The debugger is still rough, true, but improving. Apple just isn't spending the resources needed to bring lldb up to a great experience in a timely fashion.
Swifts build system can split off enough threads to consume all of your CPU cores, and batch mode did improve things, but it's not actually doing so efficiently. There is a trade off between total compute time used and number of threads used. In compute time consumed, swift is the most efficient when it's single threaded in WMO mode, but this means you can only compile in parallel with separate modules that don't depend on each other. And even then it's not a very fast compiling language itself, multithreading issues notwithstanding
Maybe something has changed recently, but as far as Xcode 12 goes, I haven't noticed much of a difference. I last checked deeply with swift 4.
More details here: https://github.com/apple/swift/blob/master/docs/CompilerPerf...
Combine (Apple's Rx framework) is pretty understandable/usable as well.
When done right, when you actually need the observer pattern, and use it as an event queue I'm sure it's probably amazing though.
https://journal.stuffwithstuff.com/2015/02/01/what-color-is-...
BUT it doesn't change the fact that Rx is hard to implement correctly and is often misused when you don't need the observer pattern.
Swift supports LSP now, so you can use VS Code if that's your thing.